Boeing Co. has suspended delivery of four commercial jet models and might have to repair hundreds of planes already in service to correct a flaw in a cockpit shield that failed federal flame tests, the aerospace giant said today.

Delivery of 34 new 747, 757, 767 and 777 model planes will be delayed "a few days" to ensure that their drip shields, which keep moisture from seeping into the cockpit, are assembled according to the design approved by the Federal Aviation Administration, said Jeff Hawk, director of airplane certification at Boeing's commercial airplane division.

Although the drip shield succeeded in protecting the cockpit from condensation, it failed FAA flame tests, proving less resistant to fire than first thought, Hawk said.

"Condensation is going where it is supposed to go," Hawk said. "As assembled, the flammability characteristics are not as favorable as when the parts are properly assembled."

Hawk said the announcement, which came during an investigation into the cause of Sunday's crash of an EgyptAir Boeing 767-300ER plane off the coast of Massachusetts, was unrelated to that disaster.

The drip shield is a hard, three-layer cap on the front of an airplane made of Kevlar or fiberglass and plastic. The version in service on the models in question was improperly bonded at Boeing's Spokane, Wash., facility, Hawk said.

Hawk stressed that the drip-shield flaw had not caused any problems on Boeing planes already in service.

"We do not see that there are any immediate safety issues with the drip shields currently in service," Hawk told reporters by telephone. "We are in the process of making changes early in production" to conform to FAA specifications.

Boeing has not yet estimated the cost of correcting the problem and declined to identify which customers will see delivery of their planes delayed.

The delays will not affect production and Boeing still expects to deliver a record 620 jets this year, Hawk said.